电力系统可靠性评估中的抽样方法研究

【作者】 王晶；

【导师】 谭震宇；

【作者基本信息】 山东大学 ， 电工理论与新技术， 2007， 硕士

【摘要】 电力系统可靠性是其规划、设计、运行和维修的重要标尺之一。电力系统可靠性评估的基本方法有解析法和蒙特卡罗法两种。解析法精度较高，但计算规模随系统元件数目增长呈指数规律增加，适用于结构简单的小型电力系统，难以在大型系统中应用。蒙特卡罗法可靠性指标的准确估计与系统规模无关，适用于大型的电力系统。蒙特卡罗法主要不足之处在于计算时间和计算精度的相关性，即为了获得精度较高的可靠性指标，往往需要很长的模拟时间。蒙特卡罗法在电力系统可靠性评估中具有良好的应用前景，由于工程实践中对评估算法计算精度越来越高的要求，研究各种改进的抽样算法以提高计算效率已成为一个具有一定理论意义和应用价值的研究课题。本文详细描述了蒙特卡罗法的原理和算法步骤。对电力系统可靠性评估中所采用的等分散抽样法、重要抽样法和自适应算法的算法原理及实现步骤作了介绍，分析了各种改进的抽样方法的优缺点及其适用的计算环境，以IEEE标准测试系统RTS提供的数据为例，应用C语言编制实现上述算法的程序软件，并进行了大量模拟计算，对这些方法作了系统的计算比较研究。提出了将解析法与蒙特卡罗法相结合的混合算法应用于发电系统的可靠性评估。该方法操作简单、移植性强。对IEEE标准测试系统RTS所作的评估计算表明了该方法在提高模拟效率上的有效性。本文进一步提出了将混合法与等分散抽样法相结合的评估方法，模拟计算表明了该方法在减少试验方差和快速收敛方面的效果更好。采用改进的抽样方法使蒙特卡罗法在电力系统可靠性评估中的计算速度有较大提高。蒙特卡罗法及其改进方法可以广泛用于大型电力系统可靠性评估。更多还原

【Abstract】 Power system reliability is one of the important rods for the plan, design, operation and maintenance of power system. There are two basic methods for the reliability evaluation of power system. These two methods are the analytical method and Monte Carlo simulation, respectively. The analytical method is of the higher precision, but its computational scale becomes large in the index rule with increasing system part numbers. The analytical method is, therefore, suitable for the reliability evaluation of small-scale power system with simple structure. Monte Carlo simulation can be favorably used to evaluate the reliability of large-scale power system because of its computational quantities being independent of the system scale. The shortcoming of Monte Carlo method is that it will take a great deal of the computation time when the high computation precision is required. Due to the requirement for increasing the accuracy of evaluation algorithm in the project practice, to improve sampling algorithm so as to enhance efficiency of the evaluation has become an important topic with certain theoretical significance and practical value. In this paper, the general principles and algorithm of Monte Carlo method used for the reliability evaluation of power system have been described in detail and the several methods applied usually to reliability evaluation of power system are presented. These methods are average-scattered sampling method, importance sampling method and adaptive algorithm, respectively, and their principles and algorithms have been also outlined systematically. The analyses on the characteristics and applicable computing circumstance of above algorithms have been made. Taking IEEE-RTS as an example, which is regarded as the standard testing system, the state of system has been simulated based on the above methods. The simulation program has been constructed using C code and the large number of the calculations has been performed. All the methods mentioned above were compared systematically, according to various calculated results. Also, the mixed method with the combination of the analytical method and Monte Carlo simulation are proposed for the reliability evaluation of generating system. The mixed method is a simple and is of strong transplant. From the standard testing system IEEE-RTS, the evaluated results of reliability show the efficiency of the mixed method for speeding up the convergence of the simulated indexes under the required precision. Further, a combination of average-scattered sampling technique with mixed method is given for reliability evaluation of generating system. By the evaluated results for IEEE-RTS system, it is clear that this new method is useable for reducing the sampling variance and accelerating the convergence of iteration calculation.In summary, to adopt the improved approach of sample can increases the simulation speed of Monte Carlo method in the reliability evaluation of power system. The methods given in this paper can be widely used for large-scale power system.更多还原